There was a term I learned in filmmaking class called “Intertextualization.” Basically, it’s material from one work which crosses over to another.
The obvious example present day is the Marvel and DC Universe movies where superheroes and villains are used in several titles. A little more subtly is “Forgetting Sarah Marshall” and “Get Him to the Greek,” both of which share one supporting character Aldous Snow, played by Russell Brand. John Wayne as Rooster Cogburn and Paul Newman in “The Hustler” and “The Color of Money” would be another.
The point to me bringing this up is crossing over characters. Sometimes you’ve written something in your past and presently you may be stuck for a new idea. Sometimes that new idea can come to you by digging out a previous character and extending their own story.
When I was mostly writing screenplays, I wrote one work called “Whitebred.” The main character’s boyfriend was a chap named Denny, and I took Denny’s story into his own movie which I called “Wonderbred.” Since his group of friends was the same as those in Whitebred, all my character development was built in and away I went with a new work.
When I started the switch to stageplays, I wrote a script called “24 Hours and Something Original.” A couple years later, I came up with a play solely because I wanted to write a story which took place in a recording studio. I was having trouble devising a plot however.
So I once again dig through things I’d already written looking for a couple characters to spark a story for my recording studio setting. I eventually figured Dennis, my young creator of the animated TV show Nantucket from my “24 Hours…” script, who continues his story into what I titled “The Twilight of Nantucket,” which centered around the voiceless talent of the TV show and Dennis makes his new appearance at the end where he gets to stick it to my villain executive character, also from “24 Hours…”
Now to be honest, I’m not exactly certain “The Twilight of Nantucket” is as good a play as “24 Hours…”. However, I am confident that the later show does stand on its own. Meaning, a reader or audience member wouldn’t need to have seen “24 Hours…” to understand what’s going on in “The Twilight of Nantucket.” And at least those two characters from the first story helped fuel my idea for the second story, even though they are only a part of the climax.
So if you ever get stuck when developing a new idea, try dusting off characters you’ve already developed for other works and see where they may fit. Some times new characters need a little mentoring and can spark plot points to extended the life of people you’ve already invented.